Getting into the tricky stuff would be how to know where you want your anaerobic capacity to be for a specific race. Is there testing that can show this?
There are two issues with anaerobic capacity (we also refer to it as VLamax) that are not issues with aerobic capacity (VO2 max). The first is how to measure it. The second is how strong should it be for a particular event. Then there is a third issue which applies to aerobic capacity as well as anaerobic capacity. Namely, how to train each system.
Neither of these first two issues with anaerobic capacity are issues with aerobic capacity or VO2 max. While it requires some elaborate equipment to measure aerobic capacity, the measurement can be done by trained personnel. Also the strength of aerobic capacity is not an issue as the stronger the better. There is never enough aerobic capacity and the concept of strength of system is obvious for its benefits. The only issue is that in reaching a max, the activity to do so may hurt other aspects of training for an event. For example, high level soccer players should have a high VO2 max but game skills are more important to success so it is obvious that a coach would not spend time getting an absolute max for aerobic capacity
Anaerobic capacity is very different as it involves the utilization of glucose for energy in the muscles. There is no direct way to measure this process as with the consumption of oxygen for aerobic capacity. So while it is happening there is an issue of how to measure it. What ever way is done, it will be less precise than the methods used to measure aerobic capacity. The second issue is that the strength of the system rarely wil be maximal in order to be optimal. In fact a strong anaerobic capacity for a distance athlete is detrimental. Suppressing it to a low level even if possible is not desirable either as the aerobic system needs pyruvate/lactate for faster contraction. Using just fats will slow you down.
Some people are experimenting with different ways to measure anaerobic capacity. Jan Olbrecht uses one way while some others use different approaches. A few people including Olbrecht use the model of metabolism developed at the Sports School in Cologne. At this moment a software program is in final development that will use lactate testing as an input and will output the VO2 max and VLamax of the athlete and show threshold as an output based on these measures.
This will hopefully eliminate the difficulty of estimating VLamax and make it more accessible for the average athlete.